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114 lines
3.2 KiB
C
114 lines
3.2 KiB
C
/*
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* copyright (c) 2005-2012 Michael Niedermayer <michaelni@gmx.at>
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*
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* This file is part of FFmpeg.
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*
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* FFmpeg is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* FFmpeg is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with FFmpeg; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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/**
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* @file
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* @addtogroup lavu_math
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* Mathematical utilities for working with timestamp and time base.
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*/
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#ifndef AVUTIL_MATHEMATICS_H
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#define AVUTIL_MATHEMATICS_H
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#include <stdint.h>
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#include <math.h>
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#ifndef M_E
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#define M_E 2.7182818284590452354 /* e */
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#endif
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#ifndef M_LN2
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#define M_LN2 0.69314718055994530942 /* log_e 2 */
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#endif
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#ifndef M_LN10
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#define M_LN10 2.30258509299404568402 /* log_e 10 */
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#endif
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#ifndef M_LOG2_10
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#define M_LOG2_10 3.32192809488736234787 /* log_2 10 */
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#endif
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#ifndef M_PHI
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#define M_PHI 1.61803398874989484820 /* phi / golden ratio */
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#endif
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#ifndef M_PI
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#define M_PI 3.14159265358979323846 /* pi */
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#endif
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#ifndef M_PI_2
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#define M_PI_2 1.57079632679489661923 /* pi/2 */
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#endif
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#ifndef M_SQRT1_2
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#define M_SQRT1_2 0.70710678118654752440 /* 1/sqrt(2) */
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#endif
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#ifndef M_SQRT2
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#define M_SQRT2 1.41421356237309504880 /* sqrt(2) */
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#endif
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#ifndef NAN
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#define NAN av_int2float(0x7fc00000)
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#endif
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#ifndef INFINITY
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#define INFINITY av_int2float(0x7f800000)
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#endif
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/**
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* @addtogroup lavu_math
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*
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* @{
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*/
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/**
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* Rounding methods.
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*/
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enum AVRounding {
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AV_ROUND_ZERO = 0, ///< Round toward zero.
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AV_ROUND_INF = 1, ///< Round away from zero.
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AV_ROUND_DOWN = 2, ///< Round toward -infinity.
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AV_ROUND_UP = 3, ///< Round toward +infinity.
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AV_ROUND_NEAR_INF = 5, ///< Round to nearest and halfway cases away from zero.
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/**
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* Flag telling rescaling functions to pass `INT64_MIN`/`MAX` through
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* unchanged, avoiding special cases for #AV_NOPTS_VALUE.
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*
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* Unlike other values of the enumeration AVRounding, this value is a
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* bitmask that must be used in conjunction with another value of the
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* enumeration through a bitwise OR, in order to set behavior for normal
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* cases.
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*
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* @code{.c}
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* av_rescale_rnd(3, 1, 2, AV_ROUND_UP | AV_ROUND_PASS_MINMAX);
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* // Rescaling 3:
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* // Calculating 3 * 1 / 2
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* // 3 / 2 is rounded up to 2
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* // => 2
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*
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* av_rescale_rnd(AV_NOPTS_VALUE, 1, 2, AV_ROUND_UP | AV_ROUND_PASS_MINMAX);
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* // Rescaling AV_NOPTS_VALUE:
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* // AV_NOPTS_VALUE == INT64_MIN
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* // AV_NOPTS_VALUE is passed through
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* // => AV_NOPTS_VALUE
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* @endcode
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*/
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AV_ROUND_PASS_MINMAX = 8192,
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};
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/**
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* @}
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*/
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#endif /* AVUTIL_MATHEMATICS_H */
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